Supplementation (noun)

1. The act or process of supplementing something.
2. The state of being supplemented.

Origin:

Late 19th century: from supplement + -ation.

Examples:

1. Vitamin supplementation is important for maintaining good health.
2. The supplementation of the diet with essential nutrients can help prevent deficiencies.
3. The company is offering a salary supplementation for employees who take on additional responsibilities.
4. The new report is a supplementation to the original study.
5. The supplementation of the workforce with temporary employees helped the company meet its deadlines.